1 /*
2  * Support for indirect PCI bridges.
3  *
4  * Copyright (C) 1998 Gabriel Paubert.
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version
9  * 2 of the License, or (at your option) any later version.
10  */
11 
12 #include <linux/kernel.h>
13 #include <linux/pci.h>
14 #include <linux/delay.h>
15 #include <linux/string.h>
16 #include <linux/init.h>
17 
18 #include <asm/io.h>
19 #include <asm/prom.h>
20 #include <asm/pci-bridge.h>
21 #include <asm/machdep.h>
22 
23 int __indirect_read_config(struct pci_controller *hose,
24 			   unsigned char bus_number, unsigned int devfn,
25 			   int offset, int len, u32 *val)
26 {
27 	volatile void __iomem *cfg_data;
28 	u8 cfg_type = 0;
29 	u32 bus_no, reg;
30 
31 	if (hose->indirect_type & PPC_INDIRECT_TYPE_NO_PCIE_LINK) {
32 		if (bus_number != hose->first_busno)
33 			return PCIBIOS_DEVICE_NOT_FOUND;
34 		if (devfn != 0)
35 			return PCIBIOS_DEVICE_NOT_FOUND;
36 	}
37 
38 	if (ppc_md.pci_exclude_device)
39 		if (ppc_md.pci_exclude_device(hose, bus_number, devfn))
40 			return PCIBIOS_DEVICE_NOT_FOUND;
41 
42 	if (hose->indirect_type & PPC_INDIRECT_TYPE_SET_CFG_TYPE)
43 		if (bus_number != hose->first_busno)
44 			cfg_type = 1;
45 
46 	bus_no = (bus_number == hose->first_busno) ?
47 			hose->self_busno : bus_number;
48 
49 	if (hose->indirect_type & PPC_INDIRECT_TYPE_EXT_REG)
50 		reg = ((offset & 0xf00) << 16) | (offset & 0xfc);
51 	else
52 		reg = offset & 0xfc;
53 
54 	if (hose->indirect_type & PPC_INDIRECT_TYPE_BIG_ENDIAN)
55 		out_be32(hose->cfg_addr, (0x80000000 | (bus_no << 16) |
56 			 (devfn << 8) | reg | cfg_type));
57 	else
58 		out_le32(hose->cfg_addr, (0x80000000 | (bus_no << 16) |
59 			 (devfn << 8) | reg | cfg_type));
60 
61 	/*
62 	 * Note: the caller has already checked that offset is
63 	 * suitably aligned and that len is 1, 2 or 4.
64 	 */
65 	cfg_data = hose->cfg_data + (offset & 3);
66 	switch (len) {
67 	case 1:
68 		*val = in_8(cfg_data);
69 		break;
70 	case 2:
71 		*val = in_le16(cfg_data);
72 		break;
73 	default:
74 		*val = in_le32(cfg_data);
75 		break;
76 	}
77 	return PCIBIOS_SUCCESSFUL;
78 }
79 
80 int indirect_read_config(struct pci_bus *bus, unsigned int devfn,
81 			 int offset, int len, u32 *val)
82 {
83 	struct pci_controller *hose = pci_bus_to_host(bus);
84 
85 	return __indirect_read_config(hose, bus->number, devfn, offset, len,
86 				      val);
87 }
88 
89 int indirect_write_config(struct pci_bus *bus, unsigned int devfn,
90 			  int offset, int len, u32 val)
91 {
92 	struct pci_controller *hose = pci_bus_to_host(bus);
93 	volatile void __iomem *cfg_data;
94 	u8 cfg_type = 0;
95 	u32 bus_no, reg;
96 
97 	if (hose->indirect_type & PPC_INDIRECT_TYPE_NO_PCIE_LINK) {
98 		if (bus->number != hose->first_busno)
99 			return PCIBIOS_DEVICE_NOT_FOUND;
100 		if (devfn != 0)
101 			return PCIBIOS_DEVICE_NOT_FOUND;
102 	}
103 
104 	if (ppc_md.pci_exclude_device)
105 		if (ppc_md.pci_exclude_device(hose, bus->number, devfn))
106 			return PCIBIOS_DEVICE_NOT_FOUND;
107 
108 	if (hose->indirect_type & PPC_INDIRECT_TYPE_SET_CFG_TYPE)
109 		if (bus->number != hose->first_busno)
110 			cfg_type = 1;
111 
112 	bus_no = (bus->number == hose->first_busno) ?
113 			hose->self_busno : bus->number;
114 
115 	if (hose->indirect_type & PPC_INDIRECT_TYPE_EXT_REG)
116 		reg = ((offset & 0xf00) << 16) | (offset & 0xfc);
117 	else
118 		reg = offset & 0xfc;
119 
120 	if (hose->indirect_type & PPC_INDIRECT_TYPE_BIG_ENDIAN)
121 		out_be32(hose->cfg_addr, (0x80000000 | (bus_no << 16) |
122 			 (devfn << 8) | reg | cfg_type));
123 	else
124 		out_le32(hose->cfg_addr, (0x80000000 | (bus_no << 16) |
125 			 (devfn << 8) | reg | cfg_type));
126 
127 	/* suppress setting of PCI_PRIMARY_BUS */
128 	if (hose->indirect_type & PPC_INDIRECT_TYPE_SURPRESS_PRIMARY_BUS)
129 		if ((offset == PCI_PRIMARY_BUS) &&
130 			(bus->number == hose->first_busno))
131 		val &= 0xffffff00;
132 
133 	/* Workaround for PCI_28 Errata in 440EPx/GRx */
134 	if ((hose->indirect_type & PPC_INDIRECT_TYPE_BROKEN_MRM) &&
135 			offset == PCI_CACHE_LINE_SIZE) {
136 		val = 0;
137 	}
138 
139 	/*
140 	 * Note: the caller has already checked that offset is
141 	 * suitably aligned and that len is 1, 2 or 4.
142 	 */
143 	cfg_data = hose->cfg_data + (offset & 3);
144 	switch (len) {
145 	case 1:
146 		out_8(cfg_data, val);
147 		break;
148 	case 2:
149 		out_le16(cfg_data, val);
150 		break;
151 	default:
152 		out_le32(cfg_data, val);
153 		break;
154 	}
155 	return PCIBIOS_SUCCESSFUL;
156 }
157 
158 static struct pci_ops indirect_pci_ops =
159 {
160 	.read = indirect_read_config,
161 	.write = indirect_write_config,
162 };
163 
164 void setup_indirect_pci(struct pci_controller *hose, resource_size_t cfg_addr,
165 			resource_size_t cfg_data, u32 flags)
166 {
167 	resource_size_t base = cfg_addr & PAGE_MASK;
168 	void __iomem *mbase;
169 
170 	mbase = ioremap(base, PAGE_SIZE);
171 	hose->cfg_addr = mbase + (cfg_addr & ~PAGE_MASK);
172 	if ((cfg_data & PAGE_MASK) != base)
173 		mbase = ioremap(cfg_data & PAGE_MASK, PAGE_SIZE);
174 	hose->cfg_data = mbase + (cfg_data & ~PAGE_MASK);
175 	hose->ops = &indirect_pci_ops;
176 	hose->indirect_type = flags;
177 }
178